A makita battery charger is flashing red with a battery plugged in, what does this mean?

SOURCE: makita dc1804f charger will not charge new i-mh 1834 18v battery

I think your tryiong to charge NIMH batteries oon a charger designed for Lithium Ion batteries. With all the new style batteries such as NICAD, NIMH and LI-ION, charging becomes difficult. Most chargers pre NIMH and LI-ion, were designed for NICAD's. The best advise, match your batteries with the correct charger

SOURCE: Need to know what the lights mean on a makita dc24sa charger

• When the battery cartridge is inserted, the charging light color will change from green to red and charging will begin.
The charging light will remain lit steadily during charging.
• One red charging light indicates charged condition in 0 – 80% and two red ones indicates 80 – 100%.
• With finish of charge, the charging lights will change from two red ones to two green ones.
• The charging time is as follows:
Battery B9017A, BH1220, BH1420, BH9020A: approx. 20 minutes.
Battery B2417, BH1233, BH1433, BH2420, BH9033A: approx. 30 minutes.
Battery B2430, BH2433: approx. 60 minutes.

SOURCE: Brand new Makita DC18RA charger wont charge the batteries.

Return to store for replacement.

SOURCE: hi i have a makita charger that flashes red and

there is a problem with the charger and given the age I would take it to an authorized dealer and get a replacement. If you give me your general area I will try and locate one close to you. Please before voting if you need more assistance let me know. Thank you

SOURCE: Makita 18v lithium battery when put on charge

This isn't true because I have a second charger and it works fine